Systems and methods for spinal rod insertion and reduction

ABSTRACT

A guide assembly includes a spinal screw assembly having a bone screw and a spinal rod holder; and a spinal rod guide having first and second elongated arc portions defining a pair of longitudinal slots extending along the first and second arc portions, each of the first and second arc portions further defining at least one recess extending transversely from each of the longitudinal slots, the at least one recess configured to receive at least a portion of a reduction tool to enable reduction of a spinal rod received within the spinal rod holder.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 12/408,684, filed Mar. 21, 2009, which claims the benefit ofpriority to U.S. Provisional Patent Application No. 61/070,290 filedMar. 21, 2008, both of which are incorporated herein by reference intheir entireties.

BACKGROUND

The present invention relates to spine fixation components, constructsand assemblies and, more particularly, to a construct for theimplantation of a spinal rod.

Spinal orthopedic assemblies and constructs such as spine plates, spinalbone screw assemblies for spinal rods and other devices (spinalcomponents) have made a profound contribution to the correction ofspinal deformities, accidents and other problems in the thoracic, lumbarand sacral spine. These and other spinal devices are fixed to vertebraeusing vertebral bone screws. Vertebral bone screws are speciallydesigned and manufactured bone screws that are placed into the bone of avertebra. One typical placement of a bone screw for the fixation of aspinal component is through a pedicle of the vertebral body. Vertebralbone screws placed in this manner offer superior strength and pull-outresistance as compared to other forms of fixation in spine surgery. Theability to achieve pedicle fixation has allowed surgeons to obtain moresecure fixation of the involved vertebral segments, which permits morepowerful correction of spine problems and reported better clinicaloutcomes. Vertebral bone screws for pedicle fixation are typically knownas pedicle screws.

Of the various spinal components, spinal rods are used in certaincircumstances to fix a number of vertebrae in a particular orientation.As such, spinal rods must be fixed to the vertebrae. The pedicle screwprovides a solid foundation for the attachment of a spinal rod. In oneform, a spinal rod may be held relative to a pedicle screw by a spinalrod connector that is coupled to the pedicle screw. The spinal rodconnector is typically rotationally connected to the pedicle screw inorder to allow various connection orientations of the spinal rodrelative to the longitudinal axis of the pedicle screw. The spinal rodconnector includes features that allow the reception and capture of thespinal rod. This is accomplished by placing the spinal rod through anopening in the body via which the pedicle screw and spinal rod connectoris attached to the vertebra. The spinal rod is then placed through thebody opening and directed into and oriented on the spinal rod connector.Thereafter, the spinal rod must be secured to each individual spinal rodconnector. This is typically accomplished by installing a spinal rodconnector screw onto the spinal rod connector via a tube temporarilyconnected to the spinal rod connector. Because of this complicatedprocedure, it is fairly difficult and/or cumbersome to situate and mounta spinal rod onto a spinal rod connector of a vertebral bone screw.

In view of the above, it is clear that there is a need for a bettermanner of mounting a spinal rod onto a spinal rod connector of avertebral bone screw.

SUMMARY

The present invention relates to a spinal rod guide for mounting aspinal rod onto a spinal rod holder of a vertebral bone screw,particularly, but not necessarily, for use in minimally invasivesurgery. The spinal rod guide is configured to extend between an openingin a patient's body and the spinal rod holder of the vertebral bonescrew, to receive a spinal rod therein, and thereafter accurately guidethe spinal rod into the spinal rod holder. The spinal rod guide isdefined by a first elongated arc portion and a second elongated arcportion that together define a first elongated slot and a secondelongated slot sized for the introduction and placement of the spinalrod into the spinal rod holder.

The first and second elongated arc portions together define an elongatedtube that allows additional spinal rod components to be guided andplaced into/onto the spinal rod connector, particularly, but notnecessarily, for securing the spinal rod into the spinal rod holder.

An embodiment of the spinal rod guide comprises a first elongated arcportion that is attachable to a spine rod holder of a spinal rod bonescrew assembly and a second elongated arc portion that is attachable tothe spine rod holder of the spinal rod bone screw assembly. First andsecond longitudinal slots are defined between sides of the first andsecond arc portions and which extend from a top of the elongated arcportions to a bottom of the elongated arc portions. The two longitudinalslots are situated at diametrically opposite sides thereof. Eachlongitudinal slot aligns with a spinal rod slot of the spinal rod holderto thereby allow easy placement of the spinal rod into the spinal rodholder. Thereafter, the elongated arc portions provide directcommunication and alignment with the top of the spinal rod holder bydefining an elongated tube in order to receive a spinal rod holder drivescrew for securing the spinal rod into the spinal rod holder. In thisembodiment, the spinal rod guide is removed from the spinal rod holderafter installation and securing of the spinal rod.

The present invention also relates to a spinal rod guide assembly formounting a spinal rod into a spinal rod holder of a vertebral bone screwassembly of the spinal rod guide assembly particularly, but notnecessarily, for use in minimally invasive surgery. The spinal rod guideassembly includes a spinal rod guide that is initially attached to thespinal rod holder of the vertebral bone screw assembly. The spinal rodguide is configured to extend from an opening in a patient's body to thespinal rod connector, to receive a spinal rod therein, and thereafteraccurately guide the spinal rod into the spinal rod connector. Thespinal rod guide defines a guide tube for the introduction and placementof additional spinal rod components onto the spinal rod connector,particularly, but not necessarily, for securing the spinal rod into thespinal rod holder. The spinal rod guide is temporarily attached to thespinal rod connector in a manner that allows for easy detachment of thespinal rod guide from the spinal rod holder.

An embodiment of the spinal rod guide assembly includes a vertebral bonescrew, a spinal rod holder pivotally coupled to the vertebral bonescrew, and an elongated guide tube defined by first and second elongatedarc portions that are attached onto a top of the spinal rod holder. Theelongated guide tube has first and second longitudinal slots extendingfrom a top of the elongated guide tube to a bottom of the elongatedguide tube that align with first and second spinal rod slots of thespinal rod holder. The two longitudinal slots of the elongated guidetube and the two spinal slots of the spinal rod holder are situated atdiametrically opposite sides. The slots allow easy placement of thespinal rod into the spinal rod holder. The elongated tube moreoverprovides direct communication and alignment with the top of the spinalrod holder in order to receive a spinal rod connector drive screw forsecuring the spinal rod into the spinal rod holder. The spinal rod guideis scored or otherwise connected at a junction between the spinal rodguide and the spinal rod holder such that the spinal rod guide is easilybroken or snapped off from the spinal rod holder once installation ofthe spinal rod is complete.

Another embodiment relates to a guide assembly comprising a spinal screwassembly comprising a bone screw and a spinal rod holder; and a spinalrod guide comprising first and second elongated arc portions defining apair of longitudinal slots extending along the first and second arcportions, each of the first and second arc portions further defining atleast one recess extending transversely from each of the longitudinalslots, the at least one recess configured to receive at least a portionof a reduction tool to enable reduction of a spinal rod received withinthe spinal rod holder.

Another embodiment relates to a spinal rod installation kit comprising aguide assembly comprising a bone screw assembly and a pair of arcuateflanges extending from the screw assembly, the arcuate flanges definingat least one longitudinal slot therebetween; a spinal rod configured tobe guided toward a fully seated position by the arcuate flanges; aspacer having a first end and a second end, the second end configured toengage the spinal rod; and a reducer configured to engage the first endof the spacer and having an inner member moveably coupled to an outermember; wherein rotation of the outer member relative to the innermember causes a longitudinal movement of the screw assembly relative tothe spinal rod.

Another embodiment relates to a method of reducing a spinal rod, themethod comprising securing a spinal rod guide assembly to a vertebralbody, the spinal rod guide assembly comprising a spinal screw assemblyand a pair of tabs extending therefrom; positioning a spinal rod betweenthe pair of tabs; positioning a spacer having first and second ends overthe spinal rod guide assembly such that the second end of the spacerengages the spinal rod; positioning a reducer such that an outer memberof the reducer engages the first end of the spacer and an inner memberof the reducer engages at least one of the pair of tabs; moving theinner member relative to the outer member to cause a correspondingmovement of the spinal screw assembly relative to the spinal rod.

Another embodiment relates to a method of installing a spinal rod, themethod comprising providing a spinal rod guide assembly having a spinalscrew and a spinal rod holder, wherein a pair of flanges extends fromthe spinal rod holder; securing the spinal screw to a vertebral body;guiding a spinal rod between the pair of flanges to a desired positionrelative to the spinal rod holder; applying a torque to the pair offlanges about a longitudinal axis defined by the pair of flanges tobreak the pair of flanges away from the spinal rod holder; and movingthe pair of flanges away from the spinal rod holder.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned and other features, advantages and objects of thisinvention, and the manner of attaining them, will become apparent andthe invention itself will be better understood by reference to thefollowing description of embodiments of the invention taken inconjunction with the accompanying drawings, wherein:

FIG. 1 is a side perspective view of an embodiment of a spinal rodguide/guide assembly in accordance with the principles of the presentinvention;

FIG. 2 is a side view of the spinal rod guide/guide assembly of FIG. 1;

FIG. 3 is a second side view of the spinal rod guide/guide assembly ofFIG. 1 taken from a side of the spinal rod guide/guide assembly that is90° from the side view of FIG. 2;

FIG. 4 is a sectional view of the spinal rod guide/guide assembly ofFIG. 1 taken along line 4-4 of FIG. 3;

FIG. 5 is a top plan view of the spinal rod guide/guide assembly of FIG.1 taken along line 5-5 of FIG. 3; and

FIG. 6 is a bottom plan view of the spinal rod guide/guide assembly ofFIG. 1 taken along line 6-6 of FIG. 3.

FIG. 7 is an exploded perspective view of a spinal rod guide assemblyaccording to an exemplary embodiment.

FIG. 8 is a side view of the assembly of FIG. 7 according to anexemplary embodiment.

FIG. 9 is a cross-section view of the assembly of FIG. 8 taken alongline 9-9 according to an exemplary embodiment.

FIG. 10 is a perspective view of a reduction kit according to anexemplary embodiment.

FIG. 11 is an exploded side view of the kit of FIG. 10 according to anexemplary embodiment.

FIG. 12 is a cross-sectional view of a portion of the kit of FIG. 10according to an exemplary embodiment.

FIG. 13 is a perspective view of a portion of the kit of FIG. 10 showinga reducer separated from a spacer according to an exemplary embodiment.

FIG. 14 is a cross-sectional view of the kit of FIG. 10 taken along line14-14 of FIG. 12 according to an exemplary embodiment.

FIG. 15 is a cross-sectional view of a reducer used in the kit of FIG.10 according to an exemplary embodiment.

FIG. 16 is a side view of a removal tool according to an exemplaryembodiment.

Like reference numerals indicate the same or similar parts throughoutthe several figures.

A description of the features, functions and/or configuration of thecomponents depicted in the various figures will now be presented. Itshould be appreciated that not all of the features of the components ofthe figures are necessarily described. Some of these non discussedfeatures as well as discussed features are inherent from the figures.Other non discussed features may be inherent in component geometryand/or configuration.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring to FIG. 1, FIGS. 1-6 depict various views of a spinal rodguide/guide assembly generally designated 10 for the introduction,placement and securing of a spinal rod relative to vertebrae of apatient. The spinal rod guide assembly 10 is defined by a vertebral bonescrew assembly 12 that is particularly, but not necessarily, a pediclebone screw assembly (pedicle screw assembly) 12 and a spinal rod guidecomponent 14. The spinal rod guide 10 is defined by the spinal rod guidecomponent 14. The spinal rod guide/guide assembly 10 is made fromtitanium, stainless steel or another biocompatible material.

In one form, the spinal rod guide 10 may be considered as the spinal rodguide component 14 and, as such, the terms are interchangeable. Inanother form, the spinal rod assembly 10 may be considered as the spinalrod guide component 14 and the pedicle bone screw assembly 12 and, assuch, the terms are interchangeable.

The pedicle bone screw assembly 12 is formed of a pedicle screw 16 and aspinal rod holder or connector 18. The pedicle screw 16 is defined by athreaded body, shank or shaft 20 with a rounded head 22. A configuredsocket 24 is provided in the screw head 22. The spinal rod connector 18is situated on the pedicle screw head 22. The spinal rod connector 18and the pedicle screw head 22 are connected such that the spinal rodconnector 18 can swivel or rotate about the pedicle screw head 22. Thisallows the spinal rod connector 18 to assume various orientationsrelative to the pedicle screw 16 in order to accommodate a spinal rod(not shown).

The spinal rod connector 18 is defined by a generally tulip-shaped body26 having a lower opening 28 that is configured to allow the pediclescrew shaft 20 to extend therethrough but to retain the pedicle screwhead 22. The pedicle screw head 22 is thus sized to be rotatablycaptured by the body 26. By virtue of its shape, the body 26 has a firstside or side member 30 and a second side or side member 32 extendingfrom a base 27 of the body 26. The first and second side members 30 and32 are separated from each other on one side by a first slot 34 and onanother side by a second slot 36. The first and second side members 30and 32 are essentially situated diametrically opposite one another onthe body 26. The first and second slots 34 and 36 are likewise situateddiametrically opposite one another on the body 26 and are sized andconfigured to receive a spinal rod therein (not shown). An upper insidesurface of the first side member 30 includes threads 31, while an upperinside surface of the second side member 32 also includes threads 33.The threads 31, 32 are configured for receiving a threaded spinal rodconnector screw (not shown) for securing the spinal rod (not shown)within the spinal rod connector 18.

The spinal rod guide component 14 is defined by a first elongated arcportion or side 42 and a second elongated arc portion or side 44 thattogether defined an elongated guide tube 40. The first and secondelongated arc portions 42 and 44 are separated from one another on oneside by a first elongated slot 50 and on another side by a secondelongated slot 52. The first and second elongated arc portions 42 and 44are essentially situated diametrically opposite one another on the guidetube 40. The first and second elongated slots 50 and 52 are likewisesituated diametrically opposite one another on the guide tube 40 and aresized and configured to receive a spinal rod therein (not shown) andallow the spinal rod to slide down into the first and second slots 34and 36 of the spinal rod connector 18. In this manner, a spinal rod (notshown) is guided from an upper end 48 of the tube into the spinal rodconnector 18, and specifically into the first and second slots 34, 36 ofthe spinal rod connector 18, via the first and second elongated slots50, 52.

The guide tube 40 moreover defines a tubular bore 46 that extends fromthe upper end 48 to the spinal rod holder body 26. The tubular bore 46is sized to allow a pedicle screw driver to be received in the screwsocket 24 and for a spinal rod holder screw (not shown) to be placedinto the spinal rod connector 18 and be threadedly received by the firstand second inner threads 31, 33 of the first and second sides 30. 32 ofthe spinal rod connector body 26 in order to secure a spinal rod (notshown) therein. Other components may also be placed through the guidetube 40.

The spinal rod guide component 14 is shown having a first taper 54 on alower end of the first elongated arc portion 42 of the guide tube 40 anda second taper 56 on a lower end of the second elongated arc portion 44of the guide tube 40. It should be appreciated that such tapers are notnecessary.

In one embodiment, the spinal rod guide component 14 of the spinal rodguide assembly 10 and, more particularly, the guide tube 40 is formedwith or made to the spinal rod holder 18. Particularly, the lower end ofthe first elongated arc portion 42 of the guide tube 40 is formed withor made to the second side 32 of the spinal rod holder body 26 while thelower end of the second elongated arc portion 44 of the guide tube 40 isformed with or made to the first side 30 of the spinal rod holder body26. A first junction or juncture 55 is defined between the lower end ofthe first elongated arc portion 42 of the guide tube 40 and the secondarc portion 32 of the spinal rod holder body 26. The first juncture 55is scored or otherwise fashioned such that the first elongated arcportion 42 can break away or snap off from the second side 32. Likewise,a second junction or juncture 57 is defined between the lower end of thesecond elongated arc portion 44 of the guide tube 40 and the first side30 of the spinal rod holder body 26. The second juncture 57 is scored orotherwise fashioned such that the second elongated arc portion 44 canbreak away or snap off from the first side 30. In this manner, when thespinal rod is set and secured in the spinal rod holder 18, the spinalrod guide component 14 may be removed.

In another embodiment, the spinal rod guide 14 may be attached orattachable to a spinal rod connector 18 by threads or another means.Particularly, the lower end of the first elongated arc portion 42 of theguide tube 40 may include threads that are threadedly received bythreads on the second end 32 of the spinal rod holder body 26. Likewise,the lower end of the second elongated arc portion 44 of the guide tube40 may include threads that are threadedly received by threads on thefirst end 30 of the spinal rod holder body 26. Thus, when the spinal rodis set and secured in the spinal rod holder 18, the spinal rod guide 14may be threadedly removed from the spinal rod holder 18.

The inside surface, interior or inner lumen of the first and second arcportions (guide tube) may also include threads or threading along their(its) length. This allows a locking cap for the spinal rod holder to bethreaded down the guide tube such that the locking cap pushes the spinalrod down into the spinal rod holder along with the locking cap to securethe spinal rod into the spinal rod holder. This also provides a mannerto reduce a spondylolisthesis condition.

The present spinal rod guide/guide assembly allows easy installation ofa spinal rod into one and/or a plurality of spinal rod connectors ofpedicle screws and the fixing thereof utilizing a minimally invasivesurgical technique.

FIGS. 7-16 show a spinal rod guide/guide assembly according to variousexemplary embodiments. Referring to FIGS. 7-9, a spinal rod guideassembly 110 (e.g., a guide assembly, a spinal fixation assembly, etc.)is shown and includes a screw assembly 112 (e.g., a bone screw assemblysuch as a vertebral bone screw assembly) and a spinal rod guidecomponent 114 (e.g., a spinal rod guide, etc.). Assembly 110 is similarto spinal rod guide assembly 10 shown in FIGS. 1-6, and may include anyof the features described with respect to spinal rod guide assembly 10and FIGS. 1-6.

Spinal rod guide 114 includes a pair of arcuate members, or tabs 142,144 (e.g., flanges, extensions, arc members, etc.) that define a pair oflongitudinal slots 150, 152. Tabs 142, 144 define a generallycylindrical shaped cross-section and have a longitudinal axis 151 (seeFIG. 9). Tab 142 includes a pair of transverse slots, or recesses, 162,166. Similarly, tab 144 includes a pair of transverse slots, or recesses160, 164. The length of tabs 142, 144, the width of slots 150, 152, arethe size and position of recesses 160-166 may be varied according tovarious alternative embodiments. Referring to FIG. 8, tabs 142, 144 maybe fixedly coupled to connector 118 via one or more welds 165 (e.g.,laser welds, ultrasonic welds, resistance welds, etc.). For example,according to one embodiment, each tab 142, 144 is coupled to connector118 via three laser welds, although more or fewer welds, or differenttypes of welding techniques (e.g., resistance welding, ultrasonicwelding, etc.) may be used in alternative embodiments. As discussed ingreater detail below, welds 165 provide a rigid connection between tabs142, 144 that may later be sheared, or broken, via application of torqueto tabs 142, 144. According to other exemplary embodiments, tabs 142,144 may be coupled to connector 118 by a single continuous weld,adhesive, or a cold-formed bond. Alternatively, tabs 142, 144 may beintegrally formed with connector 118.

According to an exemplary embodiment, screw assembly 112 includes ascrew 116 (e.g., a pedicle screw) and a spinal rod holder or connector118. Connector 118 includes a body 126 and a securing member 117.Securing member 117 threadingly engages the interior of body 126 tocaptively secure screw 116 in a rotatable fashion to connector 118. Asshown in FIG. 8, body 126 may have a tulip shape, as also discussed withrespect to connector 18. For example, body 126 may include a bulgeportion 119 (see FIG. 8) that has a diameter greater than the diameterof the top and/or bottom of body 126. In some embodiments, a portion ofconnector 118 (e.g., bulge portion 119) has a diameter greater than thediameter defined by tabs 142, 144 (e.g., a cylinder encompassing tabs142, 144). This may minimize the required skin incision and reducemuscle trauma relative to more invasive systems. Also, the tulip-shapedbody is configured to allow a greater degree of freedom for theinsertion angle and orientation of connector 118. As shown in FIG. 9,connector 118 is configured to receive a spinal rod 121. Spinal rod 121may be made of any appropriate material, and have any diameter andlength to suit a particular application.

As also discussed with respect to FIGS. 1-6, screw 116 is configured tobe secured to a bone (e.g., a vertebral body) of a patient. Screw 116 iscaptively held by connector 118. Connector 118 is in turn configured toreceive spinal rod 121, which is secured to connector 118 via a fastener(not shown). Spinal rod 121 may be guided into position using spinal rodguide 114, such that spinal rod 121 may be slid down within slots 150,152 and between tabs 142, 144. Once in position, the fastener (notshown) is tightened to secure spinal rod 121 in place within connector118.

In some situations, various factors (spinal irregularities,spondylolisthesis, etc.) may prevent the proper “seating” of spinal rod121 within connector 118. In other words, in some cases spinal rod 121may not be positionable adjacent to surface 115 (see FIG. 7) ofconnector 118, and will instead be positioned at some distance (e.g., 1mm, 5 mm, etc.) from surface 115 and a “fully seated” position. In suchinstances, it may be necessary to “reduce” the spinal rod to the fullyseated position, as discussed in greater detail below.

Referring now to FIGS. 10-16, various components and methods forreducing a spinal rod are showing according to various exemplaryembodiments. As shown in FIG. 11, a kit 169 for reducing a spinal rod isshown according to en exemplary embodiment, and includes a guideassembly 110, a spacer 190, and a reducer 170. As discussed in detailherein, kit 169 is usable to fully reduce a spinal rod such as spinalrod 121 to a fully seated position. In some embodiments, kit 169 isconfigured to reduce spinal rod 121 a maximum of 20 mm. According tovarious other embodiments, kit 169 may be configured to providereduction of greater or lesser amounts.

Referring to FIGS. 10-13, spacer 190 (e.g., a counter-torque wrench ormember, etc.) is a generally cylindrical member having a hollow,cylindrical body 192, a first end 194, and a second end 196. End 196includes a pair of notches or recesses 198 configured to receive spinalrod 121 and prevent rotation of spinal rod 121 relative to spacer 190.End 194 may include a hexagonal or other shaped portion configured toprevent relative rotation between spacer 190 and one or more portions ofreducer 170.

According to an exemplary embodiment, reducer 170 includes a pair ofouter members shown as a knob 172 and a sleeve 174, and an inner membershown as shaft 176. Reducer 170 is configured to engage spacer 190 andguide assembly 110 such that reducer 170 enables a user to reduce spinalrod 121 relative to guide assembly 110.

Referring to FIGS. 11 and 15, knob 172 is threadingly coupled to shaft176 such that rotation of knob 172 causes a corresponding movement(e.g., longitudinal or translational movement) of shaft 176 relative toknob 172. Knob 172 may take any appropriate shape and/or size and bemade of any appropriate material.

Sleeve 174 is slidably positioned on shaft 176. According to oneembodiment, sleeve 174 is configured such that shaft 176 may freelyslide longitudinally within sleeve 174, but shaft 176 may not rotaterelative to sleeve 174. For example, a pin or other extension may extendfrom the exterior of shaft 176 and be received within a longitudinallypositioned slot on sleeve 174 such that longitudinal, but notrotational, relative movement is permitted between sleeve 174 and shaft176. Thus, as knob 172 is rotated, shaft 176 moves, or translates, in alongitudinal manner relative to sleeve 174.

According to one embodiment, shaft 176 of reducer 170 includes a pair ofextensions 178, with each extension 178 including a tab 180. Extensions178 are formed in an arcuate fashion such that the curvature ofextensions 178 and tabs 180 generally matches the curvature of tabs 142,144. Furthermore, the outside diameter of extensions 178 is configuredto provide a snug, but sliding fit of extensions 178 within the interiorof spacer 190 (which may have a cylindrically-shaped interior).Furthermore, in order to prevent inward deflection of extensions 178and/or tabs 142, 144, a cylindrical guide rod 171 (e.g., a switchingstick) may be introduced within tabs 142, 144 (see FIG. 10). Asdiscussed in greater detail below, this may facilitate maintaining aproper interface between extensions 178/tabs 180 and tabs 142, 144.

In order to reduce spinal rod 121, spacer 190 is slid over guideassembly 110 such that notches 198 receive spinal rod 121. If desired,center guide or switching stick 171 may be introduced within tabs 142,144. Reducer 170 is positioned such that extensions 178 slide betweentabs 142, 144 (e.g., within longitudinal slots 150, 152) untilextensions 178 may be rotated such that tabs 180 are received withinrecesses 160, 162 in tabs 142, 144. According to one embodiment, tabs180 and recesses 160, 162 have complimentary shapes such thatlongitudinal movement of extensions 178 and tabs 180 causes acorresponding longitudinal movement of tabs 142, 144, and in turn,connector 118. In other embodiments, tabs 180 and recesses 160, 162 mayprovide a bayonet-type connection. When reducer 170 is positioned, end182 of sleeve 174 engages end 194 of spacer 190 so as to preventrelative longitudinal or rotational movement between sleeve 174 andspacer 190. Furthermore, according to one embodiment, sleeve 174 andshaft 176 may be keyed to one another so as to permit longitudinal, butnot rotational, movement between the components.

With reducer 170 and spacer 190 in proper position, knob 172 of reducer170 may be rotated (e.g., in a clockwise fashion) upon shaft 176,causing shaft 176 to move upward (e.g., away from a patient's body)through knob 172 and sleeve 174, thereby pulling spinal rod guideassembly 110 upward in a corresponding manner due to the engagement oftabs 180 with recesses 160, 162. Thus, as knob 172 is rotated, thedistance between connector 118 and line A shown in FIG. 10 is decreased(in effect, pulling the bone screw and the vertebral body toward theuser/physician). At the same time, spacer 190, due to its engagement atend 194 with sleeve 174 and its engagement at end 196 with spinal rod121, maintains a constant distance between spinal rod 121 and line Ashown in FIG. 10. In other words, as knob 172 is rotated, shaft 176 andtabs 142, 144 move upward within spacer 190, thereby moving connector118 toward spinal rod 121, which is held in place by spacer 190. Uponfurther rotation of knob 172, connector 118 will eventually be moved asufficient distance relative to spinal rod 121 such that spinal rod 121is in a fully seated position and may be fastened into place.

Providing a reduction kit such as kit 169 provides advantages over moreconventional reduction techniques. For example, tabs 142, 144 serve thedual purposes of guiding spinal rod 121 into position, and enabling auser to reduce spinal rod 121 if necessary, thereby reducing the numberof tools, fixtures, etc., required for a spinal fixation procedure.Furthermore, because the reduction components are all contained withinspacer 190, the procedure is minimally invasive and does not requireadditional access space, etc., in order to reduce the spinal rod.

Referring now to FIG. 16, a removal tool 200 is shown according to anexemplary embodiment. As shown in FIG. 16, tool 200 includes a handle202, a generally cylindrical shaft 204 extending from handle 202, and anumber of pins, or extensions, 206, 208, extending from shaft 204.According to one embodiment, extensions 206, 208 are sized and locatedsuch that when tool 200 is inserted into guide assembly 110, extensions206, 208 may be received within recesses 160-166. As such, rotation oftool 200 will generate a corresponding torque on tabs 142, 144. In someembodiments, recesses 160-166 may be provided at an angle other than 90degrees relative to the length of tabs 142, 144 such that as tool 200 isrotated, the tool tends move “upward” along the recesses. As such, botha rotational and longitudinal force may be applied to the tabs. Uponapplication of sufficient torque/force, tabs 142, 144 are configured toseparate (e.g., break away, shear from, etc.), connector 118, such thattabs 142, 144 may be removed from a procedural area. While in someembodiments tabs 142, 144 are removed by applying a torque via tool 200,according to other embodiments, other methods of removing tabs 142, 144may be used, including pulling tabs 142, 144 straight off (e.g., alongthe longitudinal axis of the tabs), bending the tabs inward/outward,etc. In some embodiments, tabs 142, 144 are moved in a non-bendingmanner during removal (e.g., via rotational about their longitudinalaxis, via puling along their longitudinal axis, a combination thereof,etc.).

Tool 200 and guide assembly 110 provide an easy and minimally invasivemeans for removing tabs 142, 144 from connector 118. In contrast toother techniques, which may require bending, rocking, or othermanipulation of various components against the surrounding muscle, bone,tissue, etc., tool 200 is configured to be received within tabs 142,144, such that in one embodiment rotation of tool 200 is the onlyforce/torque required to break away tabs 142, 144 from connector 118.Furthermore, no additional tools, etc. are required to break away andremove tabs 142, 144.

The systems and methods described herein provide may provide manybenefits over more traditional means of installing and reducing spinalrods and similar components. For example, tabs 142, 144 act as rigidfenestra without the concern of the tabs falling off during a procedure,due to the rigid, laser-welded connection of the tabs to the spinal rodholder. Further, the components provide a minimally invasive techniquethat minimizes the trauma to the patient and the length of the procedure(e.g., as a result of the easy removal feature of the tabs, etc.).

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly exemplary embodiments have been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

1. A guide assembly comprising: a spinal screw assembly comprising abone screw and a spinal rod holder; a spinal rod guide comprising firstand second elongated arc portions defining a pair of longitudinal slotsextending along the first and second arc portions, each of the first andsecond arc portions further defining at least one recess extendingtransversely from each of the longitudinal slots, the at least onerecess configured to receive at least a portion of a reduction tool toenable reduction of a spinal rod received within the spinal rod holder.2. The guide assembly of claim 1, wherein the first and second arcportions are welded to the spinal screw assembly and configured to breakaway from the spinal screw assembly upon a predetermined amount oftorque being applied to the first and second arc portions about alongitudinal axis defined by the first and second arc portions.
 3. Theguide assembly of claim 2, wherein the at least one recess is furtherconfigured to receive a portion of a removal tool, the removal toolrotatable such that rotation of the removal tool results in torque beingapplied to the first and second elongated arc portions via the recess.4. The guide assembly of claim 2, wherein the spinal screw is configuredto be secured to a vertebral body, and wherein the first and secondelongated arc portions are configured to break away from the spinalscrew after the spinal screw is secured to the vertebral body.
 5. Theguide assembly of claim 1, further comprising the reduction tool, thereduction tool comprising at least one extension configured to bereceived within the at least one recess.
 6. The guide assembly of claim5, wherein the reduction tool comprises a first member configured toengage a spinal rod received in the spinal rod holder and a secondmember comprising the at least one extension, wherein movement of thesecond member relative to the first member causes a correspondingmovement of the spinal screw assembly relative to the spinal rod.
 7. Theguide assembly of claim 6, wherein the first member comprises a sleeveand a knob, wherein rotation of the knob causes translational movementof the first member relative to the sleeve.
 8. The guide assembly ofclaim 1, wherein for each of the first and second arc portions, the atleast one recess comprises a first recess and a second recess spacedapart from the first recess, the first recess configured to receive areduction tool to enable a user to reduce a spinal rod received withinthe spinal rod holder, the first recess and second recesses configuredto receive a removal tool to enable a user to break away the first andsecond arc portions from the spinal rod holder.
 9. The guide assembly ofclaim 1, wherein the spinal rod holder comprises a tulip-shaped body.10. A spinal rod installation kit comprising: a guide assemblycomprising a bone screw assembly and a pair of arcuate flanges extendingfrom the bone screw assembly, the arcuate flanges defining at least onelongitudinal slot therebetween; a spinal rod configured to be guidedtoward a fully seated position by the arcuate flanges; a spacer having afirst end and a second end, the second end configured to engage thespinal rod; and a reducer configured to engage the first end of thespacer and having an inner member moveably coupled to an outer member;wherein rotation of the outer member relative to the inner member causesa longitudinal movement of the bone screw assembly relative to thespinal rod.
 11. The kit of claim 10, wherein the outer member of thereducer comprises a knob and a sleeve, wherein rotation of the knobabout the inner member causes the inner member to move longitudinallyrelative to the sleeve
 12. The kit of claim 11, wherein the sleeve isconfigured to engage the spacer such that the spacer and the sleeve arerotationally fixed relative to each other.
 13. The kit of claim 11,wherein the inner member of the reducer includes at least one extension,the extension configured to engage a corresponding recess extending fromthe at least one longitudinal slot.
 14. The kit of claim 13, wherein theat least one extension comprises a pair of extensions and the recesscomprises a pair of recesses, each recess configured to receive one ofthe extensions.
 15. The kit of claim 10, wherein each of the arcuateflanges is welded to the bone screw assembly and configured to breakaway from the bone screw assembly upon application of a torque to theflanges about the longitudinal axis of the flanges.
 16. The kit of claim15, wherein each of the arcuate flanges is laser-welded to the bonescrew assembly at a plurality of different locations
 17. A method ofreducing a spinal rod, the method comprising: securing a spinal rodguide assembly to a vertebral body, the spinal rod guide assemblycomprising a spinal screw assembly and a pair of tabs extendingtherefrom; positioning a spinal rod between the pair of tabs;positioning a spacer having first and second ends over the spinal rodguide assembly such that the second end of the spacer engages the spinalrod; positioning a reducer such that an outer member of the reducerengages the first end of the spacer and an inner member of the reducerengages at least one of the pair of tabs; moving the inner memberrelative to the outer member to cause a corresponding movement of thespinal screw assembly relative to the spinal rod.
 18. The method ofclaim 17, further comprising rotating the outer member relative to theinner member to cause the corresponding movement of the spinal screwassembly relative to the spinal rod.
 19. The method of claim 17, furthercomprising: removing the reducer from engagement with the spacer and thetabs; and applying a torque to the pair of tabs about a longitudinalaxis defined by the pair of tabs to cause the tabs to separate from thespinal screw assembly.
 20. The method of claim 19, wherein each tab iscoupled to the spinal screw assembly via at least one laser weld. 21.The method of claim 19, wherein the torque is applied to the pair oftabs via a tool received within the pair of tabs, and wherein onlyrotation of the tool about the longitudinal axis is required to separatethe tabs from the spinal screw.
 22. A method of installing a spinal rod,the method comprising: providing a spinal rod guide assembly having aspinal screw and a spinal rod holder, wherein a pair of flanges extendsfrom the spinal rod holder; securing the spinal screw to a vertebralbody; guiding a spinal rod between the pair of flanges to a desiredposition relative to the spinal rod holder; moving the pair of flangesin a non-bending manner to break the pair of flanges away from thespinal rod holder; and moving the pair of flanges away from the spinalrod holder.
 23. The method of claim 22, wherein moving the pair offlanges in a non-bending manner comprises applying a torque to the pairof flanges about a longitudinal axis defined by the pair of flanges. 24.The method of claim 23, wherein applying a torque to the pair of flangescomprises inserting a removal tool between the pair of flanges androtating the removal tool within the pair of flanges.
 25. The method ofclaim 24, wherein the removal tool comprises a plurality of projectionsconfigured to be received within at least one recess provided in each ofthe pair of flanges, wherein the torque is transferred from the removaltool to the pair of flanges via the interface of the plurality ofprojections and the at least one recess provided in each of the pair offlanges.
 26. The method of claim 22, wherein moving the pair of flangesin a non-bending manner comprises applying a force along a longitudinalaxis defined by the pair of flanges to move the flanges away from thespinal rod holder.
 27. The method of claim 22, wherein each of the pairof flanges is welded to the spinal rod holder.
 28. The method of claim27, wherein each of the pair of flanges is laser-welded to the spinalrod holder at a plurality of different locations.